Machine brake



W. R. CAIN.

MACHINE BRAKE. APPLICATION FILED JULY 29. ten-s.

Patented May 13, 1919.

3 SHEETS-SHEET I.

W. R. CAIN.

MACHINE BRAKE. APPLICATION HLED JULY 29, me.

1,303A60. Patented May 13,1919.

3 shins-slain a.

iva/meso- WESLEY B. CAIN, PORT J ERVIS, NEW YORK.

MACHINE-BRAKE.

' Specification of Letters Patent.

Patented May 13, 1919.

Application filed Ju1y29, 1918. Serial No. 247,292.

To all whom it may concern:

Be it known that I, WESLEY R. CAIN, a citizen of the United States,residing at Port Jervis, in the county of Orange and State of New York,have invented certain new and useful Improvementsin Machine- Brakes; andI do declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which itappertains to make and use the same. a

This invention relates to machine brakes, and it relates moreparticularly to an improved brake which I prefer to term a gravityregulator, because of its characteristics which are disclosed in thefollowing descrip tion.

The main object of this invention is to accumulate units of resistanceor breaking effect at a rate similar to the rate of aocel eration offalling bodies, and to apply such accumulation for the purpose ofregulating the speed of falling or descending elevator cars, etc.;

Another object of the invention is to uti lize the braking effect of oneset or pair of brake-shoes for bringing other brake-shoes into effectivebraking position;

Another object is to obtain a very great braking effect by the use ofcomparatively light centrifugal weights;

Another object is to provide elastic means to counteract the centrifugalforce of the weights, and tensioning means to regulate the degree ofsuch counteracting ofthe centrifugal force; and a To provide a device ofthis character which is thoroughly practical, ieficient, positive inoperation and entirely automatic;

Other objects and advantages may become,

apparent to persons who read the following details of description inconnection with the accompanying drawings in which:

Figure 1 is a view taken substantially along the line l1 of Fig. 2;

Fig. 2 is a view taken substantially along the line 22 of Fig. 1;

Fig. 3 is an end elevation of the device in its operative condition;

Fig. 41 is a view similar to Fig. 1 except this latter figure shows theparts in their operative relations, while Fig. 1 shows them inoperativeFig. '5 is a fragmental detail in side elevation;

Fig. 6 is a transverse sectional view along the line 6'-6 of Fig. 1, theparts being in their inoperative relation; and- Fig. 7 is a transversesection-a1 view along the line 7-7 o-f Fig. 4, the parts ibeing in theiroperative relation. I a

Referring t these drawings in detail, in which similar referencecharacters correspond with similar parts throughout the several views,my improved brake or gravity regulator comprises a stationary body 10which is formed with an internal annular frictional surface '11. Thisfrictional surface preferably comprises a cylindrical portion and twofrusto-conical portions 12 and 13. The body 10 is snugly apertured at 14to allow a rotary shaft 15 to extend therethrough and freely rotatetherein. The shaft 15 may be supported by any ordinary bearings (notshown), and driving and driven transmission members of any kind may besecured to said shaft, one of such members being indicated at 16. Uponthe shaft 15 is keyed or otherwise secured a rotor 17 which carries a'brake-shoe 18 at each of itsopposite ends, each brake-shoe 18 beingapertured at 19 to receive the rectangular end of the rotor. This rotoris in the shape of a bar and extends into proximity with the frictionalsurface 11, but is spaced from said friotional'surface as indicated at20.

Other brake-shoes indicated at 21, are apertured at-22 for the receptionof a second rotor. This second rotor comprises two bars 23 and 23 whichare disposed on opposite sides of the rotor 17 and are pivoted on theshaft 15 so as to have a slight rotary movement with relation to therotor 17. The bars 23 are held against movement longitudinally of thebar 15 by means of the rotor 17 and the shoes 21 into which they extend.

Each of the shoes 21 is providedwith apertures extending parallel withthe shaft 15, and through these apertures extend pins 241 which alsoextend through apertures 25 in the bars 23 and 23. F ulcrums 26 are eachapertured to receive the pins 24 and are secured thereby to respectiveshoes 21. The apertures 25 are in the form of slots which allow radialmovement of the shoes 21 along the rotor bars 23 and 23'.

The bar 23 is' provided with apertured extensions 23 to which arepivotally connected at 27 two levers 28 which are adapted to bear uponthe fulcrums 26 so as to press thebrake-shoes 21 into contact with thefrictional surface 11.

The rotor 17 is provided with pivots 29 to which are secured two pairsof levers 30 as more clearly disclosed in Figs. 6 and 7 Each of theleve-s 30 is pivotally connected at 31 to a fulcrum 32 which is securedto one of the brake-shoes 18. The bars 23 and 23 are slotted at 31 forthe reception of pins 32' which are slidable laterally of themselves andlongitudinally of slots 31. Each of these pins 32 connects thecorresponding ends of the bars 30 of one pair, so that each pair of bars30 may properly be considered a unitary lever.

One or more springs 33 are connected by suitable means to the rotor 17and to one of the bars 23 or 23 which constitute the other rotor. Thisspring 33 normally holds the rotors substantially at right angles to oneanother, or in such position that the four brake-shoes have theircenters substantially 90 degrees apart; but when the brake-shoes 21 havefrictional engagement with the frictional surface 11 and are therebyretarded, the continued rotation of the rotor 17 changes the angularrelation of these rotors, against the tension of the spring 33, and thelevers 30 are thereby swung into the position shown in Fig. 7, and thefulcrums 32 are thereby caused to press the brakeshoes 18 intofrictional engagement with the frictional surface 11, thereby greatlyincreasing the frictional resistance subsequent to the primaryapplication of resistance by the brake-shoes 21. The greater theresistance effected by the brake-shoes 21, the greater the resistanceeffected by the brake-shoes 18.

In order to automatically actuate the levers 28 when the rotors speedhas reached a predetermined rate, each of the levers 28 is movablyconnected at 34 to a weight 35, these weights being apertured at 36 forthe reception of the lever 28. The weights 35 are each preferablysemi-circular or crescent shaped, and each is provided with a pin orpivot 36 which extends through a slot 37 in one end of a lever 38. Thereare two of the levers 38, and these levers are of counterpartconstruction and pivotally mounted on the shaft 15. Each of the levers38 has both ends bifurcated to form the slots 37 and one end of eachlever 38 engages with a pivot 36 in one of the weights 35, while theother end of this lever engages a pin 36 of the other two weights, asclearly disclosed in Fig. 3. It will be seen, therefore, that theweights 35' are allowed to move along the same diametral line, inopposite directions, while being held by the levers 38 against rotarymovement with relation to one another,

thereby assuring the perfect balancing of the weights with relation tothe shaft 15.

Each of the weights 35 is apertured at 39 to receive a guide rotor 10which is keyed or otherwise secured against rotation on the shafts 15.This rotor is disposed between the levers 38 and cooperates with theweights 35 for preventing axial movement of the levers 38, while thelatter are held against axial movement by the pins 3%; it beingunderstood, however, that there is sufficient play at the pivotalconnections 3i and 27 to allow the comparatively slight swingingmovement of the levers 28. The ends of the weights 35 are reduced tosubstantially one half the width of the major part thereof, and thesereduced portions of the weights are in lapped relation to one another asdisclosed in Fig. 5, so that the corresponding, radial surfaces of theseweights are disposed in the same radial plane. These weights being ofcounterpart construction, it will be seen that they interlock so as toprevent radial movement of their ends with relation to one another.

The weights 35 and levers 28 are normally held in the inoperativeposition shown in Figs. 1, 2 and 6 by means of springs 11, connectinglink 42 and eye-bolts 43, the latter being provided with thumb nuts adfor the purpose of tensioning the springs .41 so as to increase ordiminish the resistance against the centrifugal force of the weights 35and thereby vary the speed at which the levers 28 will be actuated tomove the shoes 21 into their operative position for frictionallvengaging the surface 11.

Although I have shown the stationary member 10 in two sections andsecured together by means of screws 4-5, it is to be understood that anyother form of securing means may be employed or that the member 10 maybe formed integrally if it be found expedient to thus form it.

The operation of the device is as follows:

When the predetermined rate of speed has been reached, the weights 35are moved outward by the centrifugal force, the levers 28 are therebyswung outward, the fulcrums 26 are pressed by the levers, and the shoes21 are thereby frictionally engaged with the surface 11. This surfacebeing stationary retards the movement of members 23 and 23, and thesemembers operate through the medium of the levers 30 and fulcrums 32, topress the shoes 18 into frictional engagement with the surface 11. Whenthe speed has fallen below the predetermined rate. the weights 35 areretracted by means of the springs 11 and levers 28, the latter swinginginward and releasing the fulcrums 26, whereupon, the shoes 21 arereleased from their frictional engagement, and the springs 33 return theshoe-carrying rotors to the inoperative position shown in Figs. 1, 2 and6.

1 ,soaaco Although I have described this embodiment of my invention veryspecifically, it is to be understood that this invention is not limitedto these exact details, but I may make minor changes Within the scope ofthe inventive idea disclosed in the foregoing description and followingclaims.

What I claim as my invention is:

1. The combination of an annular frictional surface, a rotor concentricwith said frictional surface, brake shoes carried by said rotor andmovable into and out of frictional engagement with said annular surface,a second rotor rotatable with the first mentioned rotor and also capableof an independent rotary movement relative to the first mentioned rotor,brake shoes carried by the second rotor, and means operativelyconnecting the first mentioned rotor to the brake shoes of the secondrotor in such relation that the frictional engagement of the firstmentioned brake shoes effects a rotary movement thereof relative to thesecond mentioned brake shoes and thereby moves the latter intoengagement with said frictional surface.

2. The combination of an annular frictional surface, a rotor concentricwith said frictional surface, brake shoes carried by said rotor andmovable into and out of frictional engagement With said annular surface,a second rotor rotatable with the first mentioned rotor and also capableof an independent rotary movement relative to the first mentioned rotor,brake shoes carried by the second rotor, means for moving the firstmentioned brake shoes into contact with said annular frictional surface,and means operatively connecting the first mentioned rotor to the brakeshoes of the second rotor in a manner to effect movement of the secondbrake shoes into frictional engagement with said annular frictionalsurface after the first mentioned brake shoes have frictionally engagedthe said frictional surface.

3. The combination of an annular frictional surface, a rotor concentricwith said frictional surface, brake shoes carried by said rotor andmovable into and out of frictional engagement with said annular surface,a second rotor rotatable with the first mentioned rotor and also capableof an independent rotary movement relative to the first mentioned rotor,brake shoes carried by the second rotor, weights mounted for rotary andcentrifugal movements about an axis alined with the axis of said rotors,levers extending substantially parallel with said aXis and each operableby the centrifugal force of one of said Weights to effect frictionalengagement of the first mentioned brake shoes with said'annularfrictional surface, and means whereby the first mentioned rotor effectsfrictional engagement of the shoes of the second rotor with said annularfrictional surface after the first mentioned shoes have frictionallyengaged with said annular frictional surface.

4. The combination of a rotary shaft, a guide rotor mounted on andsecured against movement relative to said shaft, a pair of weightsrotatable with said guide rotor and movable radially relative theretoand guided thereby, a pair of levers each mounted for rotary movement onand relative to said shaft, means movably securing each of said leversto both of said Weights, a second pair oflevers each operable by one ofsaid Weights, an annular frictional surface, and a pair of brake shoesmovable by said second levers into frictional engagement with saidfrictional surface.

5. The combination of a rotary shaft, a guide rotor mounted on andsecured against movement relative to said shaft, a pair of weightsrotatable with said guide rotor and movable radially relative theretoand guided thereby, a pair of levers each mounted for rotary movement onand relative to said shaft, means movably securing each of said leversto both of said weights, a second pair of levers each operable by one ofsaid weights, an annular frictional surface, a pair of brake shoesmovable by said second levers into frictional engagement With saidfrictional surface, an elastic element effective to resist movement ofsaid second levers, and means for tensioning said elastic element.

6. The combination of a rotary shaft, a guide rotor mounted on andsecured against movement relative to said shaft, a pair of weightsrotatable with said guide rotor and movable radially relative theretoand guided thereby, a pair of levers each mounted for rotary movement onand relative to said shaft, means movably securing each of said leversto both of said weights, a second pair of levers each operable by one ofsaid Wei ghts, an annular frictional surface, a pair of brake shoesmovable by said second levers into frictional engagement with saidfrictional surface, a second pair of brake shoes, a third pair oflevers, and means controllable by the first said pair of brake shoes forcausing said third pair of levers to move said second pair of brakeshoes into frictional engagement with said annular frictional surface.

7. The combination of a rotary shaft, a

against a pair of levers each mounted for intov frictional engagementWith said frictional surface, a second pair of brake shoes, a third pairof levers, a guide for the first said; pair of brake shoes, and a guidefor the second said pair of brake shoes, one of said guides beingmovable With relation to the other and around said shaft, said thirdpair of levers being movably connected to each of said guides and to thesecond pair of brake shoes in such relation that the frictionalengagementof one of said pairs of shoes With said frictional surfacecauses the other pair of shoes to frictionally engage said frictionalsurface.

In testimony whereof I have hereunto set 15 my hand in the presence oftwo subscribing Witnesses.

WESLEY R. GAIN.

Witnesses:

CHARLES O. YOUNG, EDWARD P. J ONES.

Copies of this patent maybe obtained for five cents each, by addressingthe Commissioner of Patents, Washington, 13,0.

